Apparatus for expanding the ends of pipes



Dec. 30, 1952 s. RESSER APPARATUS FOR EXPANDING THE ENDS OF PIPES 6 Sheets-Sheet 1 Filed March 2, 1950 INVENTOR. LUTHE/? S. R5855? Arm/m5) D 1952 L. s. RESSER 2,623,570

APPARATUS FOR EXPANDING THE ENDS OF PIPES Filed March 2, 1950 6 Sheets-Sheet 2 I INVENTOR. LUTHER 5. RESSER ATTORNEY Dec. 30, 1952 L. s; RESSER APPARATUS FOR EXPANDING THE ENDS OF PIPES 6 Sheets-Sheet 5 Filed March 2,

INVENTOR.

. LUTHER 5. RE SER ATTORNEY Dec. 30, 1952 L. S.'RESSER 2,623,570

APPARATUS FOR EXPANDING THE ENDS OF PIPES Filed March 2, 1950 6 Sheets-Sheet 4 INVEN TOR. LUTHER 5. RESSER ATTORNEY Dec. 30, 1952 Q. RESSER 2,623,570

APPARATUS FOR EXPANDING THE ENDS OF PIPES Filed March 2, 19 50 6 Sheets-Sheet 5 INVENTOR. LUTHER 5. RESSER ATTORNEY Dec. 30, 1952 L. s. RESSER APPARATUS FOR EXPANDING THE ENDS OF PIPES 6 Sheets-Sheet 6 Filed March 2, 1950 INVENTOR. LUTHER 5. RESSER ATTORNEY Patented Dec. 30, 1952 APPARATUS FOR EXPANDING THE ENDS OF PIPES Luther S. Resser, Youngstown, Ohio; Helen W.

Resser and The Dollar Savings and Trust Company executors of said Luther S. Resser, de-

ceased Application March 2, 1950, Serial No. 147,207

4 Claims. 1

When pipes are hydraulically tested in the customary way their ends are placed in heads which snugly surround them and are provided with gaskets to form a seal for the water admitted to the interior of the pipe; in consequence the pipe extending between the heads is expanded up to approximately 2% and cold worked, but as the ends are clamped in the heads they do not receive this expansion and working and after the test are of less diameter than the main body of the pipe. It results that when the pipes are cut in the field the diameter between the ends does not coincide with that of the end of another pipe of presumably similar size while the ends themselves are untested and devoid of the cold working to which the bodies of the pipes have been subjected.

It is therefore an object of this invention to provide apparatus adapted to test and cold work the ends of a pipe and to likewise expand them the same amount that the remainder of the pipe will be expanded when subsequently subjected to the usual hydraulic expansion and test so that the pipe will then be of the same diameter and have substantially the same physical characteristics from end to end.

A further object is to provide apparatus through the medium of which one end of a pipe can be expanded substantially the same amount as the body of the pipe will be subsequently expanded through subjection to hydraulic test and the other end can be expanded to a much greater degree to provide the bell component of a bell and spigot joint with another pipe.

Further objects are to provide an apparatus of the character to which reference has been made comprising novel means for supporting and clamping the pipe in position for expansion at its ends irrespective of its wall thickness whereby a single apparatus is adapted to receive and expand pipe of various wall thicknesses and of various lengths, and to provide in such apparatus mechanisms by which the expansion of the ends is directly effected and which may be adapted for use with pipes of different diameters by simple removal and replacement of but few parts with those of other size each time that pipes of different nominal size are to be operated upon.

A still further object is the provision of apparatus embodying the foregoing characteristics which is largely automatic in character and requires but a single operative to cause it to receive a pipe, position it for expansion of its ends, eifect the expansion of the latter and then discharge it for further processing such as subjection to an hydraulic test.

Other objects, advantages and novel features of design, construction and arrangement com-- prehended by the invention are hereafter more particularly pointed out Or Will be apparent to those skilled in the art from the following description of one form of apparatus constructed in accordance therewith and illustrated in the accompanying drawings in which:

Fig. 1 is a diagrammatic top plan view of the apparatus also showing portions of a conveying mechanism desirably positioned adjacent one of its ends for receiving each pipe after it is expanded;

Fig. 2, on a larger scale, is a fragmentary front elevation of the apparatus, a pipe resting on the rolls of the roll carriages being indicated in broken lines in this figure;

Fig. 3, on a like scale, is a transverse section substantially on line 3-3 in Fig. 2;

Fig. 4 is an enlarged view of a portion of the apparatus on the same sectional plane as Fig. 3;

Fig. 5, on a much larger scale, is a top plan view of one of the roll and clamp carriages;

Fig. 6 is a side elevation thereof;

Fig. 7 is an end elevation looking to the right in Fig. 6 with certain of the parts broken away or omitted for the sake of clearness;

Fig. 8 is an end view of one of the pipe clamps and associated parts;

Fig. 9 is a top plan view thereof Fig. 10 is a vertical section showing the pipe clamping mechanism on the line IBI 0 in Fig. 9;

Fig. 11 is a fragmentary view corresponding to a portion of Fig. 8 showing the clamping fingers in open position;

Fig. ll-a is a diagrammatic view illustrating different positions assumed by the free ends of said fingers when clamping various sizes. of pipe;

Fig. 12 is a top plan view of one of the expander head buggies;

Fig. 13 is a side elevation there-of;

Fig. 14 is a view, partially in longitudinal section and partially in side elevation, of one of the expander heads;

Fig. 15 is a front end view thereof;

Fig. 16 is a central section of the tool retaining cap used when operating on pipe of large size, and

Fig. 17 is a fragmentary view generally corresponding to Fig. 14 but showing one of the expander heads arranged for expanding pipe of size larger than the head shown in Fig. 14.

General organization and operation The pipes to be expanded in the apparatus are conveniently consecutively delivered to it on the conveyor C on which they move in the direction of the arrow in Fig. 1, each pipe having been previously sized, straightened and its ends cut off and chamfered if desired. When the leading end or the first pipe reaches a point a little in advance of transverse alignment with the so called stationary expander head hereinafter described, it encounters a flag switch or other device (not shown) effective to cause the kickouts K to lift it from the conveyor rolls and move it sideways onto the skid table S, the kickout shaft i being actuated from a suitable motor and gear or crank unit M connected therewith. A manually operated switch may be provided if desired to enable the operator to actuate the kickouts should the fiag switch not function properly. The skids of the skid table are inclined downwardly and forwardly so that the pipe after transfer to them will roll down on the skids until arrested by the arms of the escapement E (shown more in detail in Fig. 4), the escapement shaft 2 being appropriately driven from a motor and gear or crank unit M which allows one pipe at a time to pass to adjustable skids S from which it moves to still other skids and finally to the rolls 3 of the roll and clamp carriages R of which two are desirably provided, these carriages being movable on tracks T and also supporting the last mentioned skids.

The rolls 3 having been previously set at the proper height the pipe is now in axial alignment with the axes of the expander heads H, H, the former of which is mounted on an expander head buggy B likewise movable on tracks T, and a this buggy is next moved along the tracks to the right in Fig. 1 until its head contacts and its expander plug enters the trailing end of the pipe. Further movement of the buggy then pushes the pipe against the expander head H which is longitudinally movable relatively to the fixed base 3 on which it is supported and, being now in advanced position, i. e. as far as possible to the left in Fig. 1, is pushed back to the right by the pipe to a small extent depending on the momentum and weight of the pipe its expander plug meanwhile telescoping in the adjacent end of the pipe. During these operations the exhaust valves of hydraulic rams A which are respectively associated with the heads are open so that both heads can attain their respectively retracted positions. Movement of the pipe to the right in Fig. 1 being thus ultimately arrested the operator, through suitable actuating mechanism, causes a pawl to drop from each side of the movable buggy B into the teeth of a rack 55 adjacent and paralleling each track rail thus locking buggy B against retrograde movement, that is movement to the left, save for the limited amount which may be required to firmly seat the pawls in the racks. The pipe clamps carried by carriages R are next raised and caused to engage the pipe at spaced intervals to thereby prevent it from subsequent buckling during the actual expanding of its ends and fiuid is admitted to the ram cylinders, the initial result of which is to move the bug y B backward until the pawls are firmly seated in the racks after which further movement of the rams actuates the expander heads to expand the ends of the pipe into which their respective expander plugs are telescoped.

The expansion being eii'ected, the plug of head H is collapsed sufficiently to free it from the pipe end, the pawls are raised, the pipe clamps opened, and buggy B then traversed rearwardly, drawing the pipe along the supporting rolls by means of its still expanded plug until the leading end of the pipe fully clears the plug of head H and a suitably disposed toggle switch 6 which operates to collapse the plug of head H and so allow the buggy and head to move away from the pipe. Thereupon another toggle switch 7 carried by the buggy is actuated as it clears the pipe and 0perates-to cause the kickouts K to lift the pipe from the rolls on carriages R, R and discharge it onto conveyor C which then translates it still farther to the right until it is aligned with a transfer table X (fragmentarily shown in Fig. l) which transfers it to another conveyor Y conveniently in alignment with conveyor C which carries it to the hydraulic testing machine or other apparatus in which it is to be subjected to further treatment.

A single cycle of the machine having thus been completed, during which both ends of a pipe P have been simultaneously expanded and cold worked, the apparatus is now in condition for repetition of the cycle on the next succeeding pipe, so that more specific reference may now properly be had to the various instrumentalities and their details of construction and operation through which are accomplished the various steps incident to each such cycle.

Escapcment mechanism As-the pipes roll down the inclined skids S from kickout mechanism K, which requires no specific description being of usual or any other construction suitable to lift the pipes consecutively from conveyor C and discharge them onto said skids, the leadin pipe encounters arms Iii of th escapement (Fig. 4) these arms being mounted on the squared longitudinally extending shaft 2 which as above mentioned is actuated from motor M. Each escapement arm at its normally uppermost extremity is provided with a finger H and at its opposite end with an abutment I2, and as shaft 2 is turned in a counterclockwise direction the pipe will roll down the body of the arm until it hits the finger while abutment i2 will rise into the path of the next succeeding pipe and hold it back on skids S. Adjacent-the escapement mechanism are a series of pedestals [3 each of which carries a downwardly inclined skid S upon which'the escapement'arms place the pipe, each skid being adjustably secured to its pedestal by pins 15 which may be passed through any of a series of holes id in the pedestal and skid so as to change the elevation and inclination of the latter at will to adapt itto receivepipe of diiierent diameters from the escapement. From skids S the pipe then passes to other-skids hereinafter described which are carried by the roll and clamp carriages.

Roll and clamp carriages Each of these carriages, of which two are, preferably provided, comprises a truck-like frame 28 mounted on four wheels 2i which rest on tracks T and so enable the carriages to be moved longitudinally thereof as required. As best. shown, in Figs. 5, 6 and '7 the frame is cut out centrally to provide an opening 22 for reception of an inner frame 23 which is pivoted at one end on a pivot 24 so its other and free endcan swing vertically; on this inner frame a roll 3 is suitably journaled i'or revolution about a horizontal axis extending transversely of the carriage and is concaved on its surface so as to form a seat for the pipe. A T-headed screw 26 normally is threaded through a lug 2"! on the main frame 26 and underlies the free end of the inner frame whereby the latter can be raised or lowered by adjusting the screw and so correspondingly raise or lower roll 3 so it will support pipes of difierent diameters in c0- axial alignment with the expander heads; it will be evident that the roll will consequently be set at a higher point for a pipe of small diameter than for a larger one. To aiford an even wider range of adjustment in this regard, a pocket 30 is formed in the main frame and the free end of the inner frame provided with a tongue 3i extending thereinto, the pocket being adapted to hold a generally rectangular filler block 32 (Fig. 7) having a threaded bore into which the T- headed screw 23 can be screwed when his desired to raise the roll to a point higher than that attainable by the screw when threaded in lug 2T.

Mention has been made of skids which receive the pipe from skids S and transfer it to the rolls 3. As best shown in Figs. 5 and 7 each of these skids 35 which are supported by the roll and clamp carriages is pivoted at 3B in pad or car 31 on the carriage inner frame and extends transversely outward therefrom toward skids S, and to facilitate angular adjustment of the skid a bracket 38 is secured to a pad or bracket 39 on th main frame and receives the lower end of a threaded clevis 43 which in turn receives and is pivoted to the outer end of the skid; thus by adjustment of the clevis the inclination of the skid can be appropriately adjusted in accordance with the size of the pipe to be received on it. Preferably to increase the range of this adjustment bracket 33 is fixed to its pad 39 in such way it can be raised or lowered with respect thereto.

Pipe clamps Each of the roll and clamp carriages R also supports a pipe clamp, hydraulically or pneumatically actuated and so constructed it is effective to grip above its axis any size pipe within the limits of the apparatus as a whole and forc the pipe snugly down against the subjacent roll 3 so that the pipe is then prevented from bending or otherwise getting out of line during the expanding of its ends.

More specifically each carriage frame 20 is provided at one end with an integral depending portion 45 which extends into a channel 46 (Fig. 3) between tracks T and in which an hydraulic or pneumatic cylinder 41 is pivotally mounted on pivots 48; a piston rod 43 extends generally upward from the piston in this cylinder and is pivoted to a head '50, and the depending portion 45 of the carriage frame is channeled out to form ways 5| in which the head is slidable vertically, the frame also being provided with openings for the passage of horizontally extending rods 52 which form bearings for certain of the links associated with the clamp fingers 55 one of which is disposed on each side of the axis of the pipe when resting on the rolls and which are shaped at their free ends approximately as shown in Figs. 8 and 10. The fingers about midway of their lengths are connected by a solid substantially U-shaped tie 56 the extremities of which are pivoted to them and which at its center is provided with a pin 5! carryin rollers 58 on its extremitieswhich also ride in ways 5|; in lieu of rollers, blocks adapted to slide in the ways may be utilized on the end of this pin. The lower extremities of the fingers are pivoted on pivots 59 to links 60 which at their other extremities are pivoted on rods 52 and consequently during the operation of the clamp move around the axes of these rods as fixed centers. The lower ends of the fingers are also pivotally connected through links 6| with head 50 with the result that when the head is reciprocated in its ways the upper ends of the fingers are opened out or moved together in such manner that whatever be the diameter of the pipe or rolls 3 the free ends of the fingers when closed upon it always engage it slightly above the horizontal plane of its axis coincident with the axis of the expander plugs and thus tend to force the pipe down against the subjacent rolls.

This action of the fingers will be readily apparent from an inspection of Figs. 8, 11 and 11a. In Fig. 3 they are shown closed on a pipe 1? of relatively small diameter and it will be noted that they engage it, as stated, somewhat above its center; in Fig. 11 they are shown open to their full extent as a result of maximum retraction of piston rod 49 in cylinder :1 and thus as they would appear preparatory to or just after a pipe has been positioned on the rolls and prior to their being closed in upon by upward projection of the piston and piston rod upon admission of fluid to the lower end of cylinder 41, while in Fig.

11a there is diagrammatically shown respectively.

Expander head mountings The movable buggy on which the expander head H is mounted and as best shown in Figs. 12 and 13 comprises a frame Hi carried on wheels H movable on tracks T and at its rear end supporting a motor 12 adapted through suitable gearing, generally designated id, to drive the adjacent wheels I I so that by operation of the motor in one direction or the other the buggy may be propelled along the tracks. At each side of the frame is a hold down M comprising a depending portion and an inwardly directed lip extending under the adjacent track rail head thus insuring the buggy constantly remaining on the tracks. The frame supports an hydraulic thruster 15 of appropriate character for raising or lowering the pawls i6 suitably mounted adjacent each side of the frame for cooperation with rack 5 of which mention has already been made. i

A motor and pump unit T! is mounted on the frame for furnishing fluid under pressure toan hydraulic ram cylinder it; which through piston rod 19 supplies the power for actuating the expander plug of the expander head H hereinafter more fully described.

In a manner generally similar to the roll and clamp carriages R, R, frame iii is cut out to receive an inner frame 23 pivoted at one end and supporting a roll 3', the frame bein vertically adjustable through the medium of mechanism like that already described in connection with frame 23 to enable roll 3' to be appropriately positioned for reception of pipe of difierent sizes. Near its forward extremity the frame is provided with a vertically extending slot for the reception of one of the kickouts K which is slidable therein and actuated from an hydraulic power cylinder and piston (not shown), the kickout when raised being effective to lift the pipe from the roll on which it is supported while being expanded and eject it to conveyor C or onto suitable skids (not shown) leading thereto. To this end the upper edge of the kickout is appropriately inclined and similar kickouts arranged for simultaneous actu.

ation areassociated witheach of the carriages- R5,..R,v andiwitli buggy; B and. base i on which OlllLtOlBCSlVG an innerframe 23" pivoted atits' outermost end for verticalmovement and sup:- porting ,a: roll 3 (Fig. 2), theframe being. arranged for vertical adjustment at its fre end similarly to the other inner frames so that the roll may be properly positioned to support a. pipe of given diameter at the level of the expander heads.

Inner frame 23" also supports the toggle switch Ii'andthe corresponding inner frame on buggy B the other toggle switch 7 which are respectively actuated at the proper points in the cycle as hitherto described.

Expander heads These heads are of generally similar construction so that with certain exceptions hereinafter noted 'adescription of one of them, for example H, more particularly illustrated in Figs. 14 and 15 will suffice for head H carried by bug y B.

More particularly each head comprises a generally hollow cylindrical housing 96 slidable on ways 80 and behind the head is disposed the ram cylinder It which through piston rod 79 furnishes the power to effect the expansion, this cylinder being appropriately connected by piping with the pump of a motor pump unit (not shown) similar to unit 'II connected with cylinder I8. Suitable valves are of course supplied for admitting to and exhausting fluid from the respective cylinders.

Piston rod I9 is connected with a plunger 9i extending axially through the housing, while surrounding this plunger is a cylindrical plunger 92, bushings 93 of suitable bearing material being respectively interposed, between plungerssi and 92 and between the latter and the housing. The rear end of the cylindrical plunger is bored out and threaded to receive a ring 9% the end of which normally projects beyond it and forms a stop for a. flange 95 on the rear end of plunger 9| while another ring 96 is similarly threaded into the rear end of the housing in alignment with aperipheral flange on the rear end of cylindrical plunger 92 provided with holes for the passage of bolts M which when in position as shown in Fig. la operatively unite the cylindrical plunger and rin as. The rear end of ring 9:2 is likewise providedwith holes 9% internally for the reception of the same or similar bolts when passed through corresponding unthreaded holes in the flange 95 so as to operatively unite, it withthe ring when desired.

Near. its forward end, that is the end remote fromconnection with rod '19, the plunger 9| is inwardly tapered and of polygonal cross-section as at 99, and supports a plurality of segmental expanding tools me. which are. heldjin place by acap WI and retaining bolt I02 threaded intothe extremity of the plunger and also by a face plate I03 bolted. to the proximate'end of the. cylindrical plunger and provided with: an annular flange Hi l overlying thezadjacent ends ofthetools, the cap and flange being of sufflcient.v internal diameter to permitthe segments to move.

outwardly. for. an adequate distanceduringtheexpanding; operation. 7

The segmental'tools asawhole constitute the expander. plug, I95 and are in number similar to the polygonal ifacescof portion'99 of'plunger BI,

the segments of course being grouped about the.

latter. The outer surface of each segment is arcuate in planes transverse to the axis of the head and parallel to that axis for a suitable distancefrom the face plate I03 adjacent which it. has atshoulder IMaLengageable with thezpipe.

end; Forwardly ofthis'pointi it .is inclined in;-

wardly to facilitate: entry of .the.plugiintothe,

pipe, each segment. also having a' finger-like portion adapted to extend into the cap IBI, while the inner surface of the segment is inclined in correspondence to the faces of the polygonal section of theplunger so as to seat snugly thereon but desirably parallel to'the axis of the head in the said finger-like portion. It results that when the plunger is retracted to the right in Fig. 14 the segments of thetool collapse inwardly while when the plunger is advanced after engagement of the tool in the pipe end the segments are forced outwardly to expand the pipe.

The-expander plugjust described is typical of thoseused for'expanding pipe ofsmaller sizes while for those of larger diameter other plugs comprising a plurality of generallysimilar but larger tool segments IIEI, Fig. 17, are provided, these segments then being operatively grouped about the end of cylindrical plunger 92 which end is likewise of polygonal'cross section, a removable face plate I I I having an annular flange I I 2 .overlying the inner ends of thetool segments when. so groupedand being bolted or otherwise removably secured to the face-of the housing 90, the flange I I2 providing appropriate clearance between the tools and itself'when the segments are in position.

It will be understood that when a smaller plug W5 is to be used the tools III] are removed but when it is desired tooperate on larger sizes of pipethe smaller toolstogether with cap IIJI and face plate I03 are-taken on and in lieu of the latter a flanged cap- II3 (Fig. 16) suitable for retainingthefingerdike ends of tools I It in-placeis substituted therefor and securedin position.

It will now be apparent that, when apipe P of size suitable for expansionbyexpandepplug Ice: is.telescoped .thereover and the piston then actuated through admission of fluid to ram cylinder I8 so as to force plunger 9I to the left in Fig.,14, the segmental expanding tools I60 are forcedradially outward inside the pipe to efie'ct its expansion, rin 9:3 being adjusted to arrest the movement of the plunger when the proper degree of expansion has been attained. However, when apipe of larger size isto be expanded through the use of the expander tools IIil, face plate I03, tools Ian and associated parts are removed as .hitherto stated and cap, I Hi substituted for-the face plate. Bolts 91 are then removed and inserted through the holes in flange 95 and the latter bolted to ring 94 so that plunger 9!,

ring iand cylindrical plunger Q2 will form an operative unit with ring 96 acting as. a stop forthis unit to arrest its movement under the influence of piston I9 when the proper degree-of p aratus is, usedfor onlyxslightlyexpanding pipe ends so as to compensate for subsequent expansion of the body between them under hydraulic test and also to efiect cold working of the ends, but when a pipe end is to be expanded to a much greater degree, as for example when forming the bell of a bell and spigot joint thereon, the edges of the expanding tools are desirably made in a spiral or at an angle to the longitudinal axis of the head to prevent marking the inside of the pipe as the expanding plug is forced into its end as will be readily understood by those familiar with this art, the precise contour of the edges of the tools being. a matter of choice and largely dictated by the work they are designed to perform.

The foregoing description of the expander heads applies equally to either of them and it has been mentioned that both heads are longi-v tudinally slidable on ways, and mean are associated with these heads to cushion the shock when the end of the pipe encounters the expander plug as it is moved thereagainst by the forward motion of the buggy B, thereby avoiding risk of injury to the ends of the pipe. The housing 90 of head H thus comprises a depending lug I20 receiving a plug I2I bearing on one end of a coil spring I22, the other end of which bears on a generally similar plug I24 received in stationary frame 4, the two plugs being desirably connected by a rod I25 and a similar construction is also provided on head H. The aforesaid shock is thus cushioned against the springs and any chance of injury to the pipe ends obviated.

Control The apparatus may readily be controlled by a single operative stationed in a pulpit positioned at some point from which he can readily observe the progress of the pipe through theapparatus and the action of the latter thereon so he may properly operate valves and other instrumentalities for effecting the various steps incident to the cycle. These valves and other instrumentalities may be of any type appropriate for the performance of their respective functions and so require neither illustration nor particular description since they are well understood in the art and readily available for association with a machine of this character. Moreover if desired some of them at least may be automatic in operation as distinguished from manually actuated, but in either case it is apparent in addition to the operations effected by switches 6, I it is necessary for the full performance of the cycle that the kickouts K raise the pipes consecutively from conveyor C; that the escapement shaft 2 be appropriately turned to allow the pipes to pass one at a time to the skids which lead them to rolls 3, which of course have been adjusted to the proper height for the size of pipe to be expanded; that buggy B be then moved toward head H, while the exhaust valves in cylinder 18 are opened; that thruster I5 be actuated to drop the pawls into the racks alongside the tracks; that clamps 55 be closed in against the pipe; that piston rods 19, I9 be moved so as to expand the expander plugs; then, after the expansion is effected, that the piston associated with the head H be retracted to collapse its plug; the clamps released and finally after the plug of head H is collapsed and cleared from the pipe and the buggy moved out of the way through automatic operation of switches 6, I, that kickouts K be raised to discharge the expanded pipe upon con- 10 veyor C and then retracted to their normal position.

Reference has been made to expanding pipes of different wall thicknesses and of diiferent diameters and it will be understood that the apparatus I have devised is Within limits substantially universal in these respects. Thus a given set of tools for example, the tools "it with their associated cap WI and face plate I63, may be suitable for expanding pipe of 6" nominal size, i. e. pipe of 6%" O. D. but of any wall thickness in that size, since the control of the effective maximum diameter of the expander plug which is afforded by the adjusting ring 94 enables the ends of the pipe to be expanded to any desired degree without regard to its wall thickness.

Likewise the tools H0 may be adapted for expanding pipe of say 16" nominal size and O. D. regardless of wall thickness, the adjusting ring 96 providing accurate control of the extent of expansion whatever be the ultimate O. D. or wall thickness.

Furthermore on simply removing the bolt I02, cap IBI, tools I09 and face plate I03 are replaceable by corresponding parts of different size for accommodating pipes of other than 6" nominal size, for example up to about 14", while an assortment of larger tools III) with corresponding caps H3 and face plates III may also be provided for expanding pipes of each nominal size from 14" to 22 and the appropriate set selected and installed in the apparatus on sim plenianipulation of their retaining bolts.

Furthermore as the degree of expansion of the pipe ends which may be-effected by this appa ratus is limited only by the expansive capacity without ruptureof the pipe wall it will be evident that pipe Which may be expanded at its ends sufiiciently to form the bell element of a bell and spigot joint may be suitably b-elled at one end with the aid of the apparatus. Preferably to form a bell, the expander plug on the stationary head before the pipe is brought against it is adjusted through control of cylinder 78 to a size corresponding to the desired ID of the bell to be produced. The pipe, secured to the expander plug of the movable bu y in the usual way is then brought against the stationary plug by movement of the buggy and with the pipe clamps adjusted to allow its limited axial movement the expander plug of the buggy is projected forwardly by operation of cylinder 18 to force the opposite pipe end over the stationary plug and thereby expand it to a bell, after which the belled pipe is discharged in the usual. way.

While I have herein described with considerable particularity one embodiment of the invention it will be understood I do not desire or intend to be thereby limited or confined thereto in any Way as changes and modifications in the form, structure, relationship and arrangement of the several parts and instrumentalitie employed will readily occur to those skilled in the art and may be made if desired without departing from the spirit and scope of the invention as defined in the appended claims.

Having thus described my invention, I claim and desire to protect by Letters Patent of the United States:

1. In apparatus of the class described, a pipe expander head comp-rising a housing, an outer plunger axially slidable therein having a tapered surface at one of its ends, an inner plunger axially slidable in the first plunger and having a tapered surface at its corresponding end, means for so lectively retaining a plurality of segmental" pipe expanding tools in engagement with the tapered surface of either plunger, means for sliding the inner plunger axially in the outer plunger, and means for releasably securing the plungers to-- gether whereby to axially slide the inner and outer plungers unita-rily with respect to the housing when the inner plunger is actuated by its said sliding means.

2. In apparatus cf the class described, a pipe expander head comprising a housing, an outer plunger axially slidable therein having a tapered surface at one of its ends, an inner plunger axially slidable in the first plunger and having a tapered surface at its corresponding end, means for selectively retaining a plurality of segmental. pipe expanding tools in engagement with the tapered surface or" either plunger, means for sliding the inner plunger axially in the outer plunger, axially adjustable means for releasably securing the outer plunger to the head, and axially adjustable means carried by said outer plunger for limiting movement of the inner plunger in one direction. 3. In apparatus or" the class described, a pipe expander head comprising a, housing, an outer plunger axially slidable therein having a tapered surface at one of its ends, an inner plunger axial-1y slidable in the first plunger and having a tapered surface at its corresponding end, means for selectively retaining a plurality of segmental pipe expanding tools in engagement with the tapered surface of either plunger, means for sliding the inner plunger axially in the outer plunger, axially adjustable means for releasably securing the outer plunger to the head, and axially adjustable means carried by said outer plunger 1'01 limiting movement of the inner plunger in one direction said last mentioned means being adapted for securernent to the inner plunger when the outer plunger is released from the head to thereby slide said outer plunger unitarily with the inner plunger when the latter is actuated by its said sliding means. 7

4 In apparatus of the class described, an expander plug comprising a plurality of coaxial substantially segmental expander toolseach hav ing opposed inner and outer tapered surfaces, the inner surface being substantially plain and the outer surface'corresponding to a segment of a surface generated by movement about the plug axis of a line disposed at an acute angle to said axis, and a movable plunger axially aligned with and extending within said plug having plane surfaces disposed angularly to the plug axis respectively corresponding to and engageable with the inner surfaces of the tools for forcing said tools radially outward from said axis, the plug including a removable tool retaining cap carried by the plunger surrounding the end portions of the tools adjacent one end of the plug and a tool retaining ring surrounding the opposite ends of the tools.

LUTHER. S. RESSER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 255,010 Nicholson Mar. 14, 1882 524,324 Higgins Aug. 14, 1894 907,396 Passat' Dec. 22, 1908 1,436,659 Klocke Nov. 28, 1922 1,451,381 Tunnell Apr. 19, 1923 1,677,860 Ferris July 17, 1928 1,879,009 Anthony Sept. 27, 1932 1,919,394 Rosenkranz July 25, 1933 2,158,312 Terrell May 16, 1939 2,359,167 Somes Sept. 26, 194-4 2,375,763 Blai-s May 15, 1945 

